Databases Reference
In-Depth Information
Limiting the use of DOM operations
Document Object Model
(
DOM
) is a convention for representing HTML objects.
With the use of DOM operations, we can change the state of HTML objects displayed
on the browser. With DOM, it will be very easy to programmatically manipulate
HTML content rendered on the browsers. Frameworks such as jQuery, AUI, or
YUI reduces the amount of code required to perform DOM operations. DOM
operations are browser-dependent. Each browser provides its own implementation
for DOM. Some of the browsers such as IE7 or IE8 are not optimized to perform
DOM operations. DOM operations slow down the rendering of web pages in the
browser. It is recommended to use fewer DOM operations in the code to make the
system run faster.
Analyzing web page performance using tools
In this section, we talked about some of the key UI best practices. UI is a very vast
field and there are many such best practices. These best practices can be applied to
any web-based applications. It is very difficult to find out areas of the UI where we
are not following such best practices. Fortunately, there are many tools available to
find out improvement areas from the UI point of view. Here are some of the more
popular tools, which we can use to find out areas of improvements:
•
YSlow
: YSlow is an open source tool to point out issues that can affect
the performance of the system. It checks the web page against around 23
rules. Based on the result it gives a performance grade. It can be installed
as a browser plugin. It supports most of the popular browsers. For more
information please refer to
http://yslow.org/
.
•
PageSpeed
: This is another web page analysis tool to point out bad practices.
It checks the pages against web page performance best practices. It is open
source and can be used as a browser plugin. It can also be configured
on Apache Web Server.
For more information please refer to
https:/
/
developers.google.com/speed/pagespeed/https:/
/developers.
google.com/speed/pagespeed/
.
•
Compuware dynaTrace AJAX Edition
: This tool installs an application
agent in the browser. With that it can record all requests. Based on the
analysis it points out areas of improvement. It also gives a performance
grade to each page. This tool persists performance reports and so it makes
it easy to compare the results after applying change
s. For more information
management/ajax-performance-testing.html
.
